Self-locking safety seal and method of identifying tampering therewith

ABSTRACT

A self-locking safety seal composed of a body, a holding device, a holder and a loop. The body includes two main parts made of light transmitting material with one of the main parts supporting the holding device and the other main part supporting the holder. The holder engages and locks with the holding device in the assembled condition of the body. The loop includes a corrugated tube which has two ends secured in the holding device. The method of detecting tampering with a self-locking safety seal including placing identification marks on inner parts of the body, photographically recording by means of an original photograph, the identification marks, photographically recording the identification marks during inspection of the seal and comparing the photographs.

United States Patent [191 Hagen Feb. 5, 1974 [54] SELF-LOCKING SAFETY SEAL AND 1,977,301 lO/l934 Bradford 292/307 R X METHOD OF IDENTIFYING TAMPERING 2,360,325 1944 Higbee 292/307 R 3,221,428 12/1965 Fischler et al. 292/307 R X THEREWITH Armin Theodor Hagen, Karlsruhe, Germany Assignee: Gesellschaft fur Kernforshung mbH,

Karlsruhe, Germany Filed: June 2, 1971 Appl. No.: 149,140

Inventor:

Foreign Application Priority Data June 11, 1970 Germany P 28 672.0

References Cited UNITED STATES PATENTS Primary Examiner-Richard E. Moore Attorney, Agent, or FirmSpencer & Kaye [57] ABSTRACT A self-locking safety seal composed of a body, a holding device, a holder and a loop. The body includes two main parts made of light transmitting material with one of the main parts supporting the holding device and the other main part supporting the holder.

The holder engages and locks with the holding device in the assembled condition of the body. The loop includes a corrugated tube which has two ends secured in the holding device.

The method of detecting tampering with a self-locking safety seal including placing identification marks on inner parts of the body, photographically recording by means of an original photograph, the identification marks, photographically recording the identification marks during inspection of the seal and comparing the photographs.

7 Claims, 2 Drawing Figures 23 fig 24 15 15 4 12 g 34 3 J2 25 26 8 5 30 PAMIEMB 51924 INVENTOR Armin Theodor Hugen ATTORNEYS.

SELF-LOCKING SAFETY SEAL AND METHOD OF IDENTIFYING TAMPERING TI-IEREWITH The present invention relates to a method of identifying tampering with self-locking safety seals used for the protection of containers holding valuable objects, e.g., fissile nuclear materials, and consisting of a body of the seal with a loop run through eyes firmly attached to individual parts of the containers to be sealed and with ends extending into the body seal, the restoration of which loop after breaking can be effected only by a replacement of components of the seal with some or all of the components of the seal equipped. with identification marks.

The use of seals serves mainly two different objectives. In one case, the main concern is proof of the genuine nature of an object, the seal in this case guaranteeing this genuine condition. In the other case, seals are used for the protection of objects, i.e., to discover unallowed tampering with these objects. These seals, which also constitute the subjectv of the present invention, are used as safety seals.

Sealing is one of several possibilities of protecting valuable objects. However, relative to other measures of protecting objects, e.g., alarm systems, safes, or guards, sealing is a simple passive means which, however, will indicate unallowed tampering with the objects to be protected only after inspection. It does not provide any prevention of or resistance against such tampering. For this reason, the main attention will be concentrated on damaging or breaking the seals in cases of tampering with the objects contained within the sealed enclosure, because broken seals will provide easier access to the objects than opening of the enclosure by force. In order to render such tampering with the seal unidentifiable, anyone attempting to break the seal will try to restore the seal to its original condition after having broken it. Since, in general, this is possible only by the use of exchange components of the seal, it is important to apply such identification marks to the components of the undamaged sea] as to make their determination or falsification futile.

The main requirements of a safety seal, subject to proper attachment of the seal to enclosures, will be listed below. Breaking of the seal should leave clearly distinguishable, irreparable damage so that restoration of the seal is possible only by means of an exchange of components of the seal. The application of identification marks to the components of the seal must clearly indicate any exchange of such components, whilst the identification marks proper should not be recognizable or at least be difficult to counterfeit. Seals should be fabricated at little expenditure, should in principle lend themselves to simple inspection in the field and require no sophisticated equipment for such inspection. In addition, a seal must at least be resistant enough to prevent normal forces, such as influences of the weather or slight mechanical touches, from breaking it. Plastictungsten seals are 'known (G.C. Fullmer, Tamper- Indicating Safing System, USAEC report RL-REA 2228, July 1965) which provide a certain amount of assurance. In that design, the loop surrounding the components of a container to be protected consists of a bimetallic wire which is introduced into a body of the seal and glued into it by means of synthetic resin glue together with the more than two components of the body of the seal which are partly screwed together. The synthetic resin glue (two component resin) contains admixtures of metal particles. The fabrication of these seals is very time consuming because the synthetic resin glue takes at least a few hours to cure without application of heat in a furnace. Also the check of such seal for integrity is rather cumbersome and can be carried out almost only in laboratories or special institutes having the necessary large-volume test equipment, such as X-ray equipment. However, any test which cannot be made in the field requires the containers under inspection to be shipped to the test equipment, which equipment certainly is not available in customs offices or at customs inspections at the borders. However, the plastic-tungsten seal described above causes such inconveniences because the loop is inspected by X-ray analysis and/or eddy current methods and the body of the seal is also tested by X-ray analysis and photography.

SUMMARY OF THE INVENTION By contrast, the present invention offers a method of sealing and identification of tampering with the seal which is characterized by the application of identification marks to inner components of the body of the seal, by photographically recording the relative positions and the structure of the identification marks by means of an original photograph through the light transmitting wall of the body of the seal, and by another photograph of the identification marks taken during inspection of the seal and its comparison with the original photograph.

An extension of the present invention provides for a device for the execution of the method which is characterized by the loop being made of a corrugated tube, whose two ends can be fastened in a holding device installed within the body of the seal, and enclosing, e.g., a wire which can be tied up within the body of the seal, and by the body of the seal consisting of two transparent main parts, a holder being attached to one of the two main parts which, in the assembled condition of the body of the seal, locks in a holding device arranged in the second main part. In one embodiment of the pres ent invention, the identification marks are made of colorless varnish containing various sizes and shapes of metal particles which can be recorded photographically by means of a Polaroid camera. In another embodiment of the invention, the main parts of the body of the seal may be made of Plexiglas or any other transparent plastic, while the wire inside the corrugated tube of the loop, which may also be transparent, can be composed of several strands. The present invention makes it impossible even to experts in sealing techniques to restore a seal once broken to its original condition without being detected. By contrast, the inspection of a seal can be carried out by any layman after short instruction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view, partly in cross section, of the body and part of the loop of the seal of one embodiment of the present invention.

FIG. 2 is a side detail view of one element of the holding device of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows part of the loop 13 and the body of the seal 14 in a sectional view. The loop 13 consists of a corrugated tube 2 made of metal or plastic with metallike properties which surrounds a wire 1. The wire 1 may consist of several intertwined strands of metal, e.g., copper. The loop 13 may be run, e.g., through eyelets (not shown) which are fixed to components of a container for shipping or storing expensive materials, e.g., FISSILE MATERIAL all parts of the container are not shown). The corrugated tube 2 may have a small diameter of a few millimeters, e.g. 10 millimeters, and can be commercially obtained in that form.

The two ends 15, 16 of the corrugated tube 2 including the wire 1 are introduced into the interior 19 of the body of the seal 14 through two openings 17, 18 of the second main part 3 (upper lid). The two openings 17, l8radially fix the two ends 15, 16 of the corrugated tube 2, these two ends in addition being introduced into two slots 11 (cf. FlG.2) of an area 20 of a holding device 4. The edges 21, 22 of the slots 11 engage into the recesses 23, 24 between two successive bulges of the corrugated tube 2 and, in the assembled condition of the body of the seal 14, hold the ends l5, 16 of the loop 13. In the assembled condition of the body of the seal 14 the ends 25, 26 of the wire 1 also extend into the interior 19 of the body of the seal 14 and can be firmly tied (knot In this connection, it is advisable to design the inner diameter of the corrugated tube 2 in such a way that the knot 5 cannot be run through.

The body of the seal 14 proper consists essentially of the one main part 8 (lower lid) and the other main part 3, each of which can be designed as a cylinder with a closing lid 27 and 28, respectively. For instance, a ring 6 may be glued to the inner wall 31 in the second main part 3 in such a way that part of the ring 6 stands out beyond the edge 30 of the second main part 3 and, with the body of the seal 14 in the assembled condition, is attached to the inner wall 29 of one main part 8 in a positive connection, thus centering the two main parts 3, 8 relative to each other.

An eye 33 of metal or plastic is attached to the inner surface 32 of the closing lid 27, for instance by gluing, which is part of the holder 9 just as the pin 7 with the head 34, which holder 9 together with the holding device 4 keep the two main parts 3, 8 in place. The pin 7 is made of plastic or metal and is expanded at its lower end 35 and supported in the eye 33. The length of the pin 7 and, especially, the distance between the inner surface 32 of the main part 8 and the lower edge of the head 34 adjacent to the pin 7 is dimensioned so that in the closed position of the body of the seal 14 the support blades 12 (cf. also FIG.2) of the holding device 4 engage behind the head 34. The two main parts 3 and 8, the holding device 9 and the ring 6 may be made of a light transmitting Plexiglas or transparent plastic material.

FIG. 2 is a more detailed representation of the holding device 4 as shown in FIG. 1. It consists of the area 20 in which the slots 11 are arranged radial to each other. At the junction of the two slots 11 there is an opening for introduction dimensioned so that the ends 15, 16 of the corrugated tube 2 can just be passed through. Two springs 36, 37 with a slight prestress (slightly bent) protrude from the area almost at right angles, their ends shaped into bent ends 38, 39 from which the two support blades 12 are bent away in an acute angle in the direction of the area 20. Their ends 40, 41 form a narrow slot through which the head 34 of the holding device 9 (according to FIG. 1) slides during assembly of the two main parts 3 and '8 of the body of the seal 14 but cannot be retracted without tearing off the support blades 12 from the holding device 4 at the bent ends 38 and 39. Also the holding device 4 may be made of metal or plastic material.

The body of the seal 14 is assembled as follows: First, the two ends 15, 16 of the corrugated tube 2 are introduced into the interior of the body of the seal 14 through the openings 17, 18 of the second main part 3. Afterwards, the ends 15 and 16, respectiveoy are successively run through the entrance opening 10 of the holding device 4 and slid sideways into one each of the slots 11. The edges 21 and 22 of the slots 11 hold the ends l5, 16 of the corrugeted tube 2 in a positive connection. Then the holding device 4 is forced into the interior of the main part 3 and the bent ends 38, 39 of the springs 36, 37 are locked in ashoulder 42. This shoulder 42 is constituted by the inner wall 31 of the main part 3 and the edge of the ring 6. The two openings 17, 18 in the closing lid 28 and the slots 11 of the holding device 4 complete the radial fixation of the two ends l5, 16 of the corrugated tube 2. However, prior to assembly of the two main parts 3 and 8 the two ends 25, 26 of the wire 1 are combined in a knot 5 within the body of the seal 14. Moreover, during assembly of the two main parts 3 and 8 the head 34 of the pin 7 is slid through the slot constituted by the two ends 40, 42 of the support blades 12. The ends 40, 41 of the support blades 12, which are also prestressed, engage behind the head 34 of the pin 7 and keep the body of the seal 14 locked.

Traces of a break of the body of the seal 14 can be removed only by exchanging components of the seal, e.g., one of the main parts 3 or 8, the pin 7, the wire 1, the corrugated tube 2, or the holding device 4. However, such exchange will be practically impossible if the components of the seal have been assigned identification marks whose forging, like forging fingerprints or the traces of bullets from the same barrel of a gun, is impossible. Identification marks of this type for the device according to the invention are dashes, dots or homogeneous areas, e.g., of colorless varnish, applied to the individual components of the body of the seal 14. The varnish in this case contains metal particles of various sizes and shapes. Of course, the identification marks are applied to the parts of the body of the seal 14 which are no longer accessible after assembly of the body of the seal 14 without breaking it, e.g., the inner surfaces 31 and/or 32 of the main parts 3 and 8. The identification marks (they are not shown in FIGS. 1 or 2) can be applied with a simple paint spray gun or even by means of a brush. In these cases, the metal particles in the varnish are arranged in a strictly random way. The position of the identification marks relative to each other, e.g., on the two main parts 3 and 8, and the structure of the identification marks and the identification marks on other parts of the body of the seal 14 are then recorded after assembly (or before) of the body of the seal 14 by means of an original photograph taken at a specific distance from the body of the seal 14 with a modified Polaroid camera. Modification of the photograph means that this camera is able to produce negatives (originals) of a reasonable size (DIN A 5) instead of prints on paper. Moreover, it is advantageous to set the camera (which also is not shown on FIGS. 1 and 2) on a support, possibly with a lighting fixture, in such a way that an equal distance to the body of the seal 14 is ensured for all photographs taken of identification marks. In addition, it is possible to set the camera to specific identification marks in the body of the seal 14 so that all photographs can be taken from the same position. A particular advantage in photographing identification marks by means of a camera lies in the fact that the inspection of the body of the seal 14 also can be carried out by means of photographs and that it can be performed at any place. Photographing the identification marks within the body of the seal 14 is possible because the materialof which at least the main parts 3 and 8 are made is a light transmitting plastic (Plexiglas). However, another possibility would be photographing the identification marks prior to assem bly of the body of the seal 14 (however, in that case excluding their position relative to each other).

Inspection of the body of the seal 14 is simple and can be performed almost anywhere. First, all components of the seal are visually inspected for damage (traces of breaks)(period) If the corrugated tube 2 is suspected of having been replaced after breaking, the wire 1 in the loop 13 can be inspected after disassembly of the body of the seal 14. If there has been a replacement of the corrugated tube 2, at least the wire 1 must have been replaced also or newly tied or joined in some other way and some other place after the break. However, replacement of the corrugated tube 2 results in the body of the seal 14 or at least the holding device 4 being damaged or, if the ends 15, 16 have been removed from slits 11, being deformed. Restoration of the concentric arrangement of the holding devise 4 relative to the openings 17, 18 in the second main part 3 is almost impossible without leaving any traces. Moreover, the position and/or structure of the identification marks at the individual parts of the body of the seal 14 are photographed in a second photograph by means of a similar camera as that used for taking the original photograph. This second photograph (also a negative) is subsequently checked for congruence of the identification marks with the original photograph. If the identification marks are correct with respect to their position relative to each other and/or their structure, it may be assumed that the body of the seal 14 was not broken.

I claim:

1. A self-locking safety seal, comprising, in combination: a body including two transparent main parts; means connecting said main parts together; said connecting means comprising a holding device installed within one of said main parts and a holder attached to the other of said main parts; and a loop comprising a corrugated tube, said tube having two ends which are secured in said holding device, and said two main parts being sealed together when said holder engages and locks with said holding device.

2. A seal as defined in claim 1, wherein said one of said main parts includes two openings therein and an inner surface, and said holding device includes a surface defining an area facing said inner surface with said area having two slots therethrough, and wherein said ends of said corrugated tube extend into the interior of said one of said main parts through said openings, with said openings holding said ends so that said ends can be firmly slid in said slots in an area facing the inner surface of the second main part, the edges of said slots engaging the corrugated tube between two adjacent corrugations thereof.

3. A seal as defined in claim 3, wherein said holder comprises a head, and wherein said holding device comprises at least two prestressed springs extending from said surface including said area and protruding into the interior of said one of said main parts, said springs including bent ends and support blades, said bent ends of said springs being adapted to expand into a shoulder formed on said inner surface of said one of said main parts, and said support blades being bent away from the bent ends in the direction of said area, wherein said support blades engage behind said head of said holder for establishing the locked condition of the body of said seal.

4. A seal as defined in claim 1, wherein said main parts of said body are made of transparent plastic material.

5. A seal as defined in claim 1, wherein said loop further comprises a wire within the corrugated tube, said wire being composed of several intertwined strands.

6. A seal as defined in claim 4, wherein said transparent plastic material is Plexiglas.

7. A method for detecting tampering with a selflocking safety seal used for the protection of containers holding valuable objects, e.g., nuclear fissile materials, the seal including a body made of light transmitting material from which a loop extends for insertion through eyelets firmly attached to individual parts of the container to be sealed and with ends extending into the body of the seal, the restoration of which loop after breakage being effected only by a replacement of components of the seal, with some or all of the components of the seal equipped with identification marks, the method comprising: placing identifiaction marks made from colorless varnish containing metal particles of different sizes and shapes which can be photographically recorded with a Polaroid camera on inner parts of the body of said seal; photographically recording by means of an original photograph taken through the light transmitting wall of said body of said seal the structure of the identification marks and the position of the identification marks relative to each other; photographically recording the identification marks during inspection of said seal; and comparing the photograph taken during inspection with the original photograph. 

1. A self-locking safety seal, comprising, in combination: a body including two transparent main parts; means connecting said main parts together; said connecting means comprising a holding device installed within one of said main parts and a holder attached to the other of said main parts; and a loop comprising a corrugated tube, said tube having two ends which are secured in said holding device, and said two main parts being sealed together when said holder engages and locks with said holding device.
 2. A seal as defined in claim 1, wherein said one of said main parts includes two openings therein and an inner surface, and said holding device includes a surface defining an area facing said inner surface with said area having two slots therethrough, and wherein said ends of said corrugated tube extend into the interior of said one of said main parts through said openings, with said openings holding said ends so that said ends can be firmly slid in said slots in an area facing the inner surface of the second main part, the edges of said slots engaging the corrugated tube between two adjacent corrugations thereof.
 3. A seal as defined in claim 3, wherein said holder comprises a head, and wherein said holding device comprises at least two prestressed springs extending from said surface including said area and protruding into the interior of said one of said main parts, said springs including bent ends and support blades, said bent ends of said springs being adapted to expand into a shoulder formed on said inner surface of said one of said main parts, and said support blades being bent away from the bent ends in the direction of said area, wherein said support blades engage behind said head of said holder for establishing the locked condition of the body of said seal.
 4. A seal as defined in claim 1, wherein said main parts of said body are made of transparent plastic material.
 5. A seal as defined in claim 1, wherein said loop further comprises a wire within the corrugated tube, said wire being composed of several intertwined strands.
 6. A seal as defined in claim 4, wherein said transparent plastic material is Plexiglas.
 7. A method for detecting tampering with a self-locking safety seal used for the protection of containers holding valuable objects, e.g., nuclear fissile materials, the seAl including a body made of light transmitting material from which a loop extends for insertion through eyelets firmly attached to individual parts of the container to be sealed and with ends extending into the body of the seal, the restoration of which loop after breakage being effected only by a replacement of components of the seal, with some or all of the components of the seal equipped with identification marks, the method comprising: placing identifiaction marks made from colorless varnish containing metal particles of different sizes and shapes which can be photographically recorded with a Polaroid camera on inner parts of the body of said seal; photographically recording by means of an original photograph taken through the light transmitting wall of said body of said seal the structure of the identification marks and the position of the identification marks relative to each other; photographically recording the identification marks during inspection of said seal; and comparing the photograph taken during inspection with the original photograph. 